U.S. patent application number 10/806583 was filed with the patent office on 2005-09-29 for particle containing solid surface material.
Invention is credited to Thompson, Jennifer L., Townsend, Lorraine A., Young, Robert Thomas.
Application Number | 20050215683 10/806583 |
Document ID | / |
Family ID | 34964451 |
Filed Date | 2005-09-29 |
United States Patent
Application |
20050215683 |
Kind Code |
A1 |
Thompson, Jennifer L. ; et
al. |
September 29, 2005 |
Particle containing solid surface material
Abstract
A liquid composition which is a precursor to a solid surface
material comprises a liquid polymerizable component and two
different solid particle distributions with an added polycarboxylic
acid or salt retarding or preventing particle settling.
Inventors: |
Thompson, Jennifer L.;
(Depew, NY) ; Townsend, Lorraine A.; (East
Amherst, NY) ; Young, Robert Thomas; (Newark,
DE) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY
LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1128
4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Family ID: |
34964451 |
Appl. No.: |
10/806583 |
Filed: |
March 23, 2004 |
Current U.S.
Class: |
524/425 ;
523/171; 524/430; 524/437 |
Current CPC
Class: |
C09D 4/06 20130101 |
Class at
Publication: |
524/425 ;
523/171; 524/430; 524/437 |
International
Class: |
C08K 003/26; C08K
003/18; C08K 003/10; C08K 003/22 |
Claims
What is claimed is:
1. A liquid casting composition which is a precursor to a solid
surface material comprising a liquid polymerizable component,
polycarboxylic acid or salt thereof having at least two carboxylic
acid groups and having a molecular weight in a range from 300 grams
per mole to 50,000 grams per mole, and solid particles wherein the
particles comprise: (a) first particles having a distribution in
the range from 1 micron to 300 microns, and (b) second particles
having a distribution in the range from 0.1 mm to 12 mm
2. The composition of claim 1 wherein said molecular weight is in a
range from 300 grams per mole to 1000 grams per mole.
3. The composition of claim 1 wherein the concentration of the acid
or salt is in a range from 0.1 to 1.0 weight percent of the liquid
polymerizable component.
4. The composition of claim 1 wherein the first particles are in a
range from 1 to 100 microns and the second particles are in a range
from 3 to 5 mm.
5. The composition of claim 1 which contains an ester of acrylic or
methacrylic acid.
6. The composition of claim 1 which contain a non-crosslinked
polymer.
7. The composition of claim 1 wherein the first particles are in a
range from 1 to 100 microns and the second particles are in a range
from 0.1 to 5 mm.
8. The composition of claim 1 wherein based on the total weight of
the composition, the first particles are present in an amount from
10 to 70 weight percent and the second particles are present in an
amount from 1 to 50 weight percent.
9. The composition of claim 8 wherein the first particles are
present in an amount from 30 to 65 weight percent and the second
particles are present in an amount from 3 to 40 weight percent.
10. A solid composition formed from the liquid coating composition
of claim 1.
Description
FIELD OF INVENTION
[0001] This invention relates to solid surface materials such as
employed in kitchen countertops and wall surfaces.
DESCRIPTION OF RELATED ART
[0002] Solid surface materials conventionally contain solid
particles embedded in a polymer. Such solid particles are employed
to impart properties such as fire retardation or solely for
aesthetic considerations.
[0003] Buser et al. U.S. Pat. No. 4,085,245 discloses preparation
of simulated granite and more particularly simulated granite
prepared from acrylic polymers and particular combinations of small
and large particles of specified distribution, shape and optical
properties.
[0004] Minghetti U.S. Pat. No. 6,177,499 discloses preparation of
polymethylmethacrylic sheets having a uniform distribution of color
both before and after thermoforming.
[0005] Atkinson U.S. 2002/0129742 discloses surface treatments for
pigments providing improved dispersability and exhibiting biocidal
activity employing a composition of a reaction product of a
halogenated carboxylic acid, an amine and optionally a fatty
acid.
[0006] A need exists for solid surface liquid formulations having a
large concentration of particles wherein settling of the particles
is retarded or preventing prior to solidification of the liquid
formulation.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a liquid casting
composition which is a precursor to a solid surface material
comprising a liquid polymerizable component and solid particles
wherein the particles comprise:
[0008] (a) first particles having a distribution in the range from
1 micron to 300 microns, and
[0009] (b) second particles having a distribution in the range from
0.1 mm to 12 mm;
[0010] wherein the casting composition further contains a
polycarboxylic acid or salt thereof having at least two carboxylic
acid groups and having a molecular weight in a range from 300 grams
per mole to 5,000 grams per mole.
[0011] Also, the present invention is directed to the resulting
solid surface material formed from the liquid coating
composition.
DETAILED DESCRIPTION OF THE INVENTION
[0012] As employed herein, a solid surface material is employed in
its normal meaning and represents a three dimensional material such
as a material particularly useful in the building trades for
kitchen countertops, sinks and wall coverings wherein both
functionality and an attractive appearance are necessary.
[0013] Liquid Polymerizable Component
[0014] A necessary component of a liquid precursor to the solid
surface material is a liquid polymerizable component.
[0015] By "liquid" is meant that the material is fluid at room
temperature. The liquid polymerizable material may include one or
more of the following: (a) at least one monofunctional monomer
reactive material; (b) at least one polyfunctional monomer reactive
material, and (c) at least one oligomeric reactive material.
[0016] Monofunctional monomer reactive material: a "monofunctional
monomer reactive material" refers to a compound having one unit of
unsaturation capable of taking part in a free radical initiated
polymerization reaction, thus becoming incorporated into a
polymeric chain. Suitable monofunctional monomer reactive materials
can include, for example, monomers having one acrylic group,
monomers having one vinyl group, monomers having one allyl group,
substituted butadienes or combinations thereof.
[0017] A preferred type of monofunctional monomer reactive material
is an ester of acrylic or methacrylic acid. The ester is generally
derived from an alcohol having 1-20 carbon atoms. The alcohols can
be aliphatic, cycloaliphatic or aromatic. The ester may also be
substituted with groups including, but not limited to, hydroxyl,
halogen, and nitro. Representative (meth)acrylate esters include
methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate,
2-ethylhexyl (meth)acrylate, glycidyl(meth)acrylate,
cyclohexo(meth)acrylate, isobornyl(meth)acrylate,
siloxane(meth)acrylates, and the like. Acrylic and methacrylic acid
can also be used. Most preferred is methylmethacrylate and
copolymers thereof.
[0018] Examples of monofunctional monomer materials including one
"vinyl group" include acrylonitrile, methacrylonitrile, and vinyl
acetate.
[0019] Polyfunctional monomer reactive material: a "polyfunctional
monomer reactive material" refers to a monomeric compound having
multiple units of unsaturation which can take part in free radical
initiated polymerization reactions, thus becoming incorporated into
two or more polymeric chains. By the nature of the resulting
structure, such a reaction is referred to as "crosslinking" in
which two or more polymeric chains are joined by the polyfunctional
monomer reactive material. As such, polyfunctional monomer reactive
materials are often referred to as crosslinking agents.
[0020] The reactive group can be one that copolymerizes with the
liquid polymerizable material, such as a polymerizable
ethylenically unsaturated group. The reactive group can also be one
that reacts with a side chain or residue of the liquid
polymerizable material after polymerization, such as a hydroxyl,
carboxyl, isocyanate or epoxy group. The reaction of the
multifunctional reactive material forms a crosslinked network with
the liquid polymerizable material.
[0021] A preferred class of crosslinking agents is the
(meth)acrylate esters of polyols. Some representative examples
include ethylene glycol di(meth)acrylate, neopentyl glycol
di(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane
tri(meth)acrylate, pentaerythritol tri(meth)acrylate,
dipentaerythritol tetra(meth)acrylate, and the like. Other suitable
types of crosslinking agents include divinyl compounds, such as
divinyl ethers, allyl(meth)acrylate, urethane di- and
poly-(meth)acrylates.
[0022] Oligomeric reactive material: an "oligomeric reactive
material" refers to an oligomeric, low molecular weight chain
having one or more units of reactivity, such as ethylenic
unsaturation, that can take part in free radical initiated
polymerization reactions, thus becoming incorporated into a
polymeric material. Oligomeric reactive materials can include
oligomers of any of the (a) and/or (b) monomers described above;
urethane(meth)acrylates formed by (meth)acrylic functionalization
of urethane oligomers or by in situ reaction of oligomeric
isocyanates with (meth)acrylic residues; (meth)acrylate
functionalized unsaturated polyester oligomers and resins;
epoxy(meth)acrylates, such as the mono- and di(meth)acrylates of
bisphenol A epoxy resins; and combinations thereof. Preferably, the
oligomeric reactive material is incorporated into the polymerized
material making up the cast article during the curing process.
Alternative reactive groups can be vinyl, allyl, and the like.
Reactive groups can be pendant to or in the main chain of the
polymer.
[0023] It is understood that oligomeric reactive materials having
more than one reactive group can also function as crosslinking
agents.
[0024] It will be appreciated that the choice of reactive materials
making up the liquid polymerizable fraction will depend to some
extent on the desired properties of the final cast article. For
example, if adhesion to a hydrophilic filler or substrate is
desired, an acrylic material with acid or hydroxyl groups can be
used. For flexibility, (meth)acrylates with lower glass transition
temperature, T.sub.g, such as butyl acrylate, can be used. For
thermal stability, it is preferred that acrylates be used in
combination with methacrylates. For enhanced hardness, it is
preferred that high T.sub.g (meth)acrylate functional oligomer be
used.
[0025] Polymer Component
[0026] The casting compositions of the present invention optionally
include at least one non-crosslinked resin polymer. Non-crosslinked
resin polymers of the present invention can be reactive,
nonreactive or a combination thereof. A non-crosslinked resin
polymer is "reactive" when the polymer physically associates or
chemically reacts with any other component(s) in the casting
composition.
[0027] The term "non-crosslinked" as used herein refers to polymers
that are linear, branched, blocked or combinations thereof, that,
as a starting material prior to introduction to the molding
composition have chains without linkages between the chains. The
non-crosslinked polymer can either be soluble or insoluble in the
liquid polymerizable material. It is preferred that the
non-crosslinked polymer is soluble in the liquid polymerizable
material. The combination of the soluble non-crosslinked polymer
dissolved in the liquid polymerizable material is generally
referred to as a "sirup". Suitable polymers include, are but not
limited to, homopolymers and copolymers made from any of the
monomers or oligomers listed above as liquid polymerizable
material.
[0028] The primary use of the non-crosslinked polymer fraction is
as a rheology modifier for the casting composition, particularly
when soluble in the liquid polymerizable fraction. In addition, the
non-crosslinked polymer fraction can also contribute to the
performance and/or aesthetics of the final cast article and can
reduce the amount of liquid polymerizable fraction required.
[0029] Polycarboxylic Acid or Salt
[0030] The necessary component in the present invention to retard
or prevent settling of solid particles is a polycarboxylic acid or
salt thereof having at least two carboxylic acid groups and having
a molecular weight in a range from 300 grams per mole to 5,000
grams per mole. A preferred range is 300 grams per mole to 1000
grams per mole.
[0031] Commercially available examples of such polycarboxylic acids
or salts include, but are not limited to BYK.RTM.-P 104, BYK.RTM.-P
104S, BYK.RTM.-P105 (available from BYK Chemie USA Incorporated,
Wallingford, Conn.), Bermawet Antifloat S (available from Bergen
Materials Corp., Elfers, Fla.), Efka 5065 and Efka 5061 (available
from EFKA Additives USA, Stow, Ohio). Illustratively, BYK.RTM.P-104
is a solution of a lower molecular weight unsaturated
polycarboxylic acid polymer; BYK.RTM.-104S is with a polysiloxane
polymer while BYK.RTM.-P-105 is a solvent free version of
BYK.RTM.-P-104. Efka 5065 is a high molecular weight unsaturated
carboxylic acid with a compatible organically modified polysiloxane
and Efka 5071 is an alkylol ammonium salt of a high molecular
weight carboxylic acid.
[0032] Without being bound to any theory it is considered that the
polycarboxylic acid or salt provides controlled flocculation of
particles by creating a three dimensional network that is easily
broken under shear. This network is considered to build up a low
shear rate viscosity such the particles settle slowly. Accordingly,
in the time period in which solidification of the liquid
formulation occurs, little or no particle settling is observed.
[0033] Although it is necessary for the polycarboxylic acid or salt
to be present, the amount of such acid or salt can vary within wide
limits. One variable which can affect the amount of acid or salt
would include the time necessary for formation of the solid surface
material. If the cure time is short, less acid or salt is necessary
since minimum settling will occur. Other variables include the
size, weight and concentration of the solid particles. Heavier
particles in the starting liquid formulation are considered to
require large concentrations of the polycarboxylic acid or salt.
However, a person in this art can readily determine any optimum
amount based on a knowledge of employing the acid or salt. A
typical concentration of carboxylic acid or salt of a liquid
polymerizable component is in a range from 0.1 to 1.0 percent by
weight, more preferably 0.125 percent by weight.
[0034] Particles
[0035] In the present invention, particles are present in two
different size distributions. It is considered that the benefits of
the present in retarding or reducing particulate settling do not
occur to the desired degree if only a single particle size
distribution is present.
[0036] A first particle size distribution is in a range from 1
micron to 300 microns, more preferably 1 to 100, and most
preferably 10 to 50 microns.
[0037] A second particle size distribution is in the range from 0.1
mm to 12 mm, more preferably 0.1 to 5 mm and most preferably 3 to 5
mm.
[0038] The concentration of the first and second particle size
distribution can vary within wide ranges. Illustratively, the first
particle size distribution may be present in an amount of 10 to 70
weight percent based on the total composition volume, more
preferably 30 to 65 weight percent and most preferably 40 to 60
weight percent. Illustratively, the second particle size
distribution may be present in an amount of 1 to 50 weight percent
based on the total composition weight, more preferably 3 to 40
weight percent and most preferably 5 to 30 weight percent. It is
understood that the liquid polymerizable component will be present
in a sufficient amount to act as a binder for all particles.
[0039] Additionally, it is understood that particle may, and
typically will, be present which lie outside the standard particle
size distribution ranges.
[0040] The composition of the first smaller particles
illustratively include mineral fillers. Some representative mineral
fillers include alumina, alumina trihydrate (ATH), alumina
monohydrate, Bayer hydrate, silica including sand or glass, glass
spheres, magnesium hydroxide, calcium sulfate, calcium carbonate,
barium sulfate, and ceramic particles. ATH, alumina monohydrate,
magnesium hydroxide, and calcium carbonate are known to have fire
retardant properties.
[0041] The second larger particles typically are added for
aesthetic reasons, i.e. to impart a pleasing surface appearance to
the final article. Illustrative particles can be colored or
uncolored, opaque, translucent, or transparent. Typical mineral
particles that can be used are calcined talc, magnetite, siderite,
ilmenite, goethite, galena, graphite, anthracite and bituminous
coal, chalcopyrite, pyrite, hematite, limonite; pyroxenes such as
augite; amphiboles such as hornblende, biotite, sphalerite,
anatase, corunbum, diamond, carborundum, anhydrite, chalk, diurite,
rutile, sandstone, shale, slate, sparite, vermiculite, natural
granite, peat and basalt. Other useful materials are chips of
brick, charcoal, concrete, plaster, porcelain, sawdust, seashells,
slag, wood and the like. Commonly employed macroscopic decorative
particles known to the industry as "crunchies" are various filled
and unfilled, pigmented or dyed, insoluble or crosslinked chips of
polymers such as ABS resins, cellulose esters, cellulose ethers,
epoxy resins, polyethylene, ethylene copolymers, melamine resins,
phenolic resins, polyacetals, polyacrylics, polydienes, polyesters,
polyisobutylenes, polypropylenes, polystyrenes, urea/formaldehyde
resins, polyureas, polyurethanes, polyvinyl chloride,
polyvinylidene chloride, polyvinyl esters and the like. Other
useful macroscopic translucent and transparent decorative particles
are natural or synthetic minerals or materials such as agate,
alabaster, albite, calcite, chalcedony, chert, feldspar, flint
quartz, glass, malachite, marble, mica, obsidian, opal, quartz,
quartzite, rock gypsum, sand, silica, travertine, wollastonite and
the like; cloth, natural and synthetic fibers; and pieces of
metal.
[0042] In the preceding discussion of the first and second particle
size distributions, it is understood that the same particle
component can be used for both the first and second particles.
However, conventionally the particle composition will differ.
Illustratively, the reason to add smaller particles may be to add
fire retardancy to the overall composition while large particles
are present for surface aesthetics.
[0043] As previously set forth it is understood that particles
outside the disclosed distribution may and conventionally can be
expected to be present.
[0044] Other Components
[0045] The liquid casting composition typically will contain
additional components such as cure agents, pigments and other
additives.
[0046] Cure agents, when activated, generate free radicals which
then initiate the desired polymerization reactions. Either a
chemically-activated thermal initiation or a purely
temperature-driven thermal initiation to cure the acrylic
polymerizable fraction may be employed herein. Both cure systems
are well-known in the art. In the embodiment of the examples, a
chemically-activated thermal initiation cure is employed.
[0047] Pigments such as iron oxides, zinc sulfide, zinc oxide, and
titanium dioxide are routinely utilized in solid surface
applications to achieve the desired color and aesthetics. These may
be added in the form of liquid dispersions or pastes or as neat,
milled solids depending upon the needs of the particular
system.
[0048] Other ingredients are included in the casting compositions
to enhance physical performance, improve processability, or adjust
visual aesthetics. Examples of such additives include the addition
of adhesion promoting agents to increase adhesion between the
filler and the polymerizing fraction. Impact modifiers, for
example, elastomeric polymers such as graft copolymers of methyl
methacrylate, styrene, and butadiene, copolymers of butyl acrylate
and methyl acrylate or other well-known impact modifiers can be
added to improve impact strength. Flame retardant additives such as
brominated organics can be incorporated. Other flame retardants
include carbon fiber and aramid fiber.
[0049] In the following examples all percentages and parts are by
weight unless otherwise indicated.
[0050] In each of the examples the following components listed in
the Table were employed. All percentages are by weight unless
otherwise indicated.
1TABLE Component Weight Methyl methacrylate, unsaturated monomer
33.62 g 24% PMMA polymer in MMA, dissolved polymer sirup 302.54 g
aluminum trihydroxide, inorganic filler 510 g white chips of
polyacrylic, decorative particles 150 g trimethylolpropane
trimethacrylate, crosslinker 1.41 g Vazo .RTM. 67, initiator 0.21 g
Lupersol 10M75, initiator 1.05 g Penn Color 9S172, 50% in MMA,
pigment 0.20 g Penn Color 9S138, 50% in MMA, pigment 0.20 g g means
grams. MMA means methyl methacrylate. PMMA means polymethyl
methacrylate with an average molecular weight in a range from
25,000 to 40,000.
[0051] Aluminum trihydrate particle size was in a range from 1 to
100 microns.
[0052] White chips particle size was in a range from 0.1 to 5
mm.
EXAMPLE 1
Control
[0053] The components listed in the Table were added to a reaction
kettle and mixed with a high-speed dispersion blade for four
minutes under vacuum. The resulting mix was poured into a 1 liter
graduated cylinder. A thermocouple was placed in the mix and the
graduated cylinder was submerged into a 60.degree. C. water bath.
The reaction temperature was monitored until the reaction was
complete, approximately 1 hr. The sample was easily removed from
the graduated cylinder upon cooling and was cut lengthwise to
observe particle settling. Almost all, i.e., more than 95% of
individual particles were concentrated in approximately one-third
of the lengthwise sections of the resulting article. Less than 5%
of individual particles were randomly present in the remaining
two-thirds portion of the lengthwise section.
EXAMPLE 2
[0054] The components listed in the Table along with 5 g of
Byk.RTM.-P105 (70% by weight lower molecular weight carboxylic acid
polymer in n-butyl methacrylate) were added to a reaction kettle
and mixed with a high-speed dispersion blade for four minutes under
vacuum. The resulting mix was poured into a 1 liter graduated
cylinder. A thermocouple was placed in the mix and the graduated
cylinder was submerged into a 60.degree. C. water bath. The
reaction temperature was monitored until the reaction was complete,
approximately 1 hr. The sample was easily removed from the
graduated cylinder upon cooling and was cut lengthwise to observe
whether particle settling took place. The lengthwise section
showed, at most, a small amount of settling took place with
uniformity present.
EXAMPLE 3
[0055] The components listed in the Table along with 5 g of
Efka.RTM. 5071 (51-55% alkylol ammonium salt of carboxylic acid)
were added to a reaction kettle and mixed with a high-speed
dispersion blade for four minutes under vacuum. The resulting mix
was poured into a 1 liter graduated cylinder. A thermocouple was
placed in the mix and the graduated cylinder was submerged into a
60.degree. C. water bath. The reaction temperature was monitored
until the reaction was complete, approximately 1 hr. The sample was
easily removed from the graduated cylinder upon cooling and was cut
lengthwise to observe whether particle settling took place. The
lengthwise section showed, at most, a small amount of settling took
place with uniformity present.
EXAMPLE 4
[0056] The components listed in the Table along with 5 g of
Efka.RTM. 5065 (50-54% unsaturated carboxylic acid combined with
organically modified polysiloxane in
alkylbenzene/diisobutylketone.) were added to a reaction kettle and
mixed with a high-speed dispersion blade for four minutes under
vacuum. The resulting mix was poured into a 1 liter graduated
cylinder. A thermocouple was placed in the mix and the graduated
cylinder was submerged into a 60.degree. C. water bath. The
reaction temperature was monitored until the reaction was complete,
approximately 1 hr. The sample was easily removed from the
graduated cylinder upon cooling and was cut lengthwise to observe
whether particle settling took place. The lengthwise section
showed, at most, a small amount of settling took place with
uniformity present.
* * * * *